TECHNICAL FIELD OF THE INVENTION
This invention relates to a device for compensating the pressures inside and outside of an immersed volume of gas, and chiefly of air. It is equipped with mobile or deformable walls whose positions are not to be affected by the depth variations of the volume.
A typical example of application comprises of underwater electroacoustic transducers used for sweeping acoustic mines.
The pressures inside and outside of the diaphragms forming the drives of these electroacoustic transducers must be kept equal in order for them to operate correctly. This is done by mounting a flexible compensation bladder in a housing on the rear of the minesweeping vehicle, with the bladder in communication with the volume to be balanced. The housing mounting means positions the housing at the general level of the volume to be compensated.
The principle of the pressure compensation device is as follows. Any variation in the depth at which the vehicle is navigating varies the hydrostatic pressure applied to the diaphragms of the electroacoustic transducers, and simultaneously compresses or expands the compensation bladder until the internal and external pressures of this volume are equalized. This compensation is performed independently and automatically, and therefore seems to be satisfactory; but it does suffer from one limitation, in that it allows a nominal navigation depth of only about 8 m, with possible 4 m variations above and below this nominal depth.